Trailers are widely used in many activities and are able to be towed behind vehicles and carry additional loads. Generally such trailers have 2 wheels, however, trailers with 4 or even more wheels, are also known.
Hitherto such trailers have been fabricated from sheet metal and where corrosion resistance is required, the sheet metal has normally been either painted or hot dipped galvanised, the latter being a particularly expensive and environmentally unfriendly activity.
In mining such trailers are used to provide movable antennae and other communications equipment to ensure a reliable local radio network throughout the mine site, particularly where blasting is being undertaken. Under these circumstances it is necessary to move the antenna and communications equipment and mounting these on a trailer ensures that the equipment can be easily and quickly move from one place to another within the mine site.
However, a particular problem with mining is that the mine sites are often particularly corrosive atmospheres which can be due to a combination of factors including high rainfall, sulphurous gases, abrasive dust, and the like. It has therefore been found that even hot dipped galvanised metal trailers will quickly corrode.
In recent years, it has been known to manufacture trailers with a metal chassis and a body fabricated from plastics material. The disclosures of U.S. Pat. No. 7,032,956 and US Patent Application US 2004/0201247 are representative of this art. In particular, whilst the body which retains the cargo in position is fabricated from the plastics material, the load-bearing chassis has continued to be manufactured from steel because of its strength. However, whilst strength is an advantage of steel, its susceptibility to corrosion is a significant disadvantage.